Electric incandescent lamp



Aug. 6, 1929. P. o. lCARTUN l ELECTRIC INCANDESCENT LAMP Filed June 9, 1925 .Hits Arraszvz's:

Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

PAUL 0. CARTUN, OF CLEVELAND HEIGHTS OHIO, ASSIGNOB TO GENERAL ELECTRIC COMBANY, .A CORPORATION OF NEW YORK.

ELECTRIC INCANDESCENT LAMP.

Application led .Tune 9,

My invention relates to electric incandescent lamps, and more particularly to improvements in the mounting and arrangements of the filaments therein.

The advantages of using in vacuum lamps closely coiled metal filaments of the type used in the gas-filled lamps disclosed .in Langmuir Patent No. 1,180,159, issued April 18, 1916, have been recognized. However, the vacuum lamp requires a less concen. trated filament than the gas-filled lamp and difficulty has been experienced` in support. ing such a filament without using a comparatively large number of support wires and this resulted in comparatively highcooling of the filament and consequent lowering of efficiency. The'object of my invention is to provide a filament andmountinv therefor so disposed as to give a desirable light distribution with a comparatively low cooling effect from filament supports and hence a comparatively high efficiency. Further advantages andl features of my invention will appear from the following description of species thereof. While my invention is of particular advantage in vacuum lamps, it is not restricted thereto and may be used to advantage in gas-filled lamps.

The 4invention is illustrated in the accompanying drawing, in which F ig. 1 is a front elevation of an electric incandescent lamp comprisin my invention; Fig. 2 is a fragmentary slde elevation thereof; Fig. 3 is a sectional plan View along the lines 3--3 of Fig. 1; Fig. 4 is a frontelevation of an electric incandescent lam comprising a modification of my invention; Fig. 5 is a fragmentary side elevation thereof; and Fig. 6 is a perspective of an electric incandescent lamp comprising still another Inodification of my invention.

Like parts are designated by the same characters of reference in all the various figures.

Referring to the drawings, 10 is a bulb lof an electric incandescent lamp havinof a base 11 at its outer end and a stem 12. Into the latter are sealed the leading-in wires'13--14 which are connected to the conductors 15-16 usually of copper or nickel. A compara tively short longitudinally extending rod 17 of glass or other insulating material is united to the stem 12 and has formed on its inner end a button 18 which has embedded therein the wires 19, 20 and 21 ordinarily of metal such as tungsten or molybdenum. The supports 19 and 20 extend longitudinallyof the lamp, and vmore specifically, are located in a plane which 1n. cludes the longitudinal ,axisof the lamp. The support 21 extends'transversely of the lamp and, more specifically lies in a plane normal to the longitudinal axis of the lamp.

The supports 19, 20 and 21 with the help of the conductors 15-16 resiliently support the filament 22. The said filament is of the closely coiled form, preferably tungsten. The filament passes through loops at the ends of the supports and is free to slide therein when the 1am is subjected to shock and to compensate or expansion or contraction arising from temperature changes.

The lamp shown in Fig. 4 dil'ers from that shown in Fig. 1 in that there is more horizontal disposition of the filament. In the lamp shown in Fig. 6, the filament has an intermediate positlon. eFurther variations maybe made in the disposition of the filament according to the general direction of distribution desired.

What I lclaim as new and desire to secure by Letters Patent of the United States, is

In an electricincandescent lamp, the combination of a support comprising a seal portion andan insulating rod extending therefrom substantially axially of said lamp, leading-in Wires having ends spaced transversely from the end of said rod, a pair of support Wires extending approximately longitudinally of the lamp from the end of said rod, a third support wire extending transverselyof'said lamp from the end oi said rod, and a filament supported solely upon the ends of the said leading-in Wires and support wires. y

In witness whereof, I have hereuhto set my hand this 6th day of June, 19251.v

PAUL O. CARTUN. 

